Method and apparatus for making building blocks



Dec. 2, 1941. D.- A. McKl-:NzlE

IIETHOD ANDPPARATUS FOR MAKING BUILDING BLOCKS Filed arch 31. 1939 4 Sheets- Sheet 1 M3! 3 f/ ZZ r. 7325/1 20./ afl.

"moum EMMA MCKEz-zzze Dec. 2, 1941. D. A. MGKENZIE 1 0D AND APPARATUS F0 R MAKING BUILDING BLOCKS Filed ual-ch 31. 1939 4 sheets-sheet 2 Fri /l/ l m W m l/Ar. "h4 o l IMJ. i d 0 u.. ,wl m@ a Dec. 2, 1941. D. A. McKENzlE 2,254,943

METHOD AND APPARATUS FOR MAKING BULDING BLOCKS Dec. 2, 1941.

D. A. MQKENZIE METHOD AND APPARATUS FOR MAKING BULDING BLOCKS Filed March 31, 1939 4 Sheelbs-J'Shee 4 a o' ,MQ/00X; Unna/d MUKE'HZZE Patented Dec. 2, 1941 UNITED S PATENT GFFICE STATE METHOD AND APPARATUS Fon MARIN BUmnlNG BLOCKS banana A. McKenzie, Milwaukee', wis.

9 Claims.

This inventlonrelates to building blocks and a method and apparatus for making the same.

The conventional vsc-called cored concrete n Application March 31, 1939, Serial No. 265,222

building block, as is well known, comprises an of such blocks are not strictly dead" air spaces,

and this invention, therefore, has as one of its objects to provide a building block of the type described having a higher insulating value due to the presence of definitelyformed spaces, which are so constructed that when the block is incorporated in a Wall, each individual space is closed at both ends so that it constitutes a dead airl space in the strict sense of the word.

Another disadvantage of the conventional y building block is that the surfaces to which the mortarfis applied are really edges of relatively small area, which not only increases the cost of laying the blocks as it is more diflicult to apply the mortar over a broken surface and much of the mortar is wasted, but the strength of the completed wall is limited by virtue of this edge to edge contact between the blocks, and the fact that the webs between adjacent openings are relatively narrow and unsupported.

With this in mind, the present invention has as another of its objects to provide a building block of greater strength due to a novel interlocking columnar formation, and one in which the surfaces to which the mortar is applied are either wholly unbroken or have only small regularly spaced openings which do not interfere with the application of the mortar, and which are closed by the mortar.

Another object of this invention is to provide a building block which is internally Vibrated during its manufacture.

It is 'also an object of this invention to provide a new and improved manner of making building blocks wherein a plurality of vibrator cores serve thel dual function of vibrating the block linternally and producing cored openings which are either closed at both ends or open at one or both vibrating the plastic mass of which the building blocks are formed, which is so designed that the number of cored openings produced thereby may be readily altered.

Another object of this invention is to provide a building block having dead air spaces formed in the manner aforesaid, and which has a facing of natural stone.

In this respect, it is a further object ,of the invention to provide an improved method of makinga building block having a natural stone facing which permits the use-of drier concrete, or more specifically, a concrete having a more correct water ratio, without jeopardizing the strength of the bond between the facing and the concrete backing.

Another object of this invention is to provide an apparatus for making concrete building blocks which is so designed that the block during its formation can be subjected to internal and form vibration. I

, With the above and other objects in view which will appear as the description proceeds, this invention resides in thenovel construction, comends, but which are definitely closed at the time l lpractical and sturdy apparatus for internally application of the principles thereof, and in which: l

Figure 1 is a vertical sectional view through an apparatus constructed in accordance with this invention, and illustrating the manner in which the vibrating cores extend down into the plastic mass during the internal vibration;

Figure 2 is a view of the apparatus taken at right angles to Figure l, and illustrating the vibrating cores lifted, and with the form prepared to receive the mass;

Figure 3 is a view similar to Figure l, with the .vibrating cores lowered as in Figure 1;

removal of excess concrete closes the open tops` ofthe cored openings;

Figure 6 shows the form b ox lowered to expose the finished block;

Figure 7 illustrates a slight modiiication of the invention in which form vibration is utilized in conjunction with the internal vibration;

Figure 8 is a perspective view of a ilnished stone faced block;

Figure 9 is a detail view illustrating the construction of the vibrating cores;.

Figure l is a perspective view of an all concrete block; and

Figure l1 is a plan view of the block shown in Figure 10, showing the arrangement of its dead air spaces in comparison to the arrangement of the cored openings of a conventional concrete building block.

Referring now particularly to the accompanying drawings in which like numerals indicate like parts throughout the several views, the numeral 5 represents a core box which is preferably arranged for vertical motion to and from an operative position coacting with a pallet 6 to form a receptacle for a mass 1 of concrete or other similar material.

It is desired to point out that where this specification and the claims refer to concrete, it is understood that the term is being used in its broad sense, and that all mixtures having a cementitious binder are included.

The form 5 may be arranged for vertical motion with relation to the pallet I5, as stated, or the pallet may be the movable part. The important thing is that relative vertical motion be provided between the form box and the pallet so that the finished block can be removed from the form.

In practicing this invention, it has been found expedient to provide arhorizontally shiftable hopper 9 which slides over the open top of the form to facilitate depositing the plastic mass into it. This hopper, as shown in Figure 5, also acts to scrape off excess concrete after the block has been formed and vibrated, and in doing so, closes the open tops of the cored openings I0 left by the withdrawal of the vibrating cores I I.

The vibrating cores II, as bestillustrated in Figure 9, have a slight downward taper and are removably secured at their upper ends to a plate I2. A similar plate I3 held in spaced relation to the plate I2 at a distance beneath it and having holes I4 through which the vibrating cores pass serves to steady and reinforce the cores.

A simple manner of quickly detachably securing the individual-cores to the plate I2 consists in the provision of a stud I5 secured in the upper end of the core and threaded to receive a clamping nut I5 which engages the top of the plate I2. In this manner, the number and arrangement oi the cores may be quickly changed.

This flexibility is desirable for the reason that in some localities, the building codes require greater compressive strength than in other iocalities, and as it is desirable to have as many dead air spaces in the block as possible, the greatest number of cores compatible with the strength requisites is always used.

The plates I2 and I3 are secured to opposite ends of bushings I'I which are slidably mounted on vertical rods I8. in a stationary supporting frame I9. Above and These rods I8 are slidable beneath the bushings I'I, the rods I8 have heavy A 'Ihe motor 25 and the bearings 2l for the shaft 2l are carried by a frame 2l. which is rigidly secured to the vertical shafts Il. This frame is supported by cables 29 trained over sheaves mounted on the stationary support I9 and connected with a drum 3l also mounted thereon in such a manner that the entire vibrator structure may be quickly raised and lowered.

Vibration is obtained through the provision of two pairs of eccentric weights Il adjustably secured to the shaft 23. In the construction illustrated. al1 of the weights are set to produce maximum vibration, and as `:vill be readily apparent, the extent of vibration can be regulated by adjusting the relative positions of the eccentric weights on the shaft 23.

The description thus far describes in detail the method and apparatus employed in the manufacture of building blocks in accordance with this invention. To briefly summarize the method of procedure, the hopper is slid into position over the empty form box. Concrete is deposited in the form box. The vibrating cores are lowered into the plastic mass and vibrated for a period of approximately twenty seconds, which is long enough to give the mass sufficient rigidity to be self-supporting, and then while vibration is continued, the cores are withdrawn from the plastic mass. It is the continuance of the vibration together with the slight taper of the cores which permits them to be withdrawn from the mass, leaving the openings desired.

After the cores are fully withdrawn, the hopper is slid back across the core box or form, which scrapes ofl the excess material and automatically closes the open tops of the holes. Thereafter, the form is pushed down, leaving the finished block in position to be removed, as shown in Figure 6.

Where the block is wholly concrete, as illustrated in Figure 10, the method just outlined is followed. If it is desired to have the block provided with a natural stone facing, as shown in Figure 8, a stone slab 35 is set in the form box, as shown in Figure 2, before the concrete is deposited therein. This divides the form with the result that the finished unit is double and is left in this double formation until the blocks are about to be shipped to their place of use, when the slab is split flatwise in a manner shown and described in Patent No. 1,893,430 issued to D. A. McKenzie, January 3, 1933.

One advantage of the present invention is that it permits the use of a drier concrete, or rather one having a more correct water ratio without jeopardizing the bond between the stone facing and the concrete backing. This follows from the fact that during vibration, the Water content of the concrete exudes outwardly toward the surfaces confining the mass, and thus provides the necessary moisture for the capillary action which brings about the bond between the stone facing and the concrete.

Where the apparatus is to be used for making stone faced blocks, as just described, it is only necessary to remove the center row of vibrating cores to accommodate the slab in the mold.

Another important advantage of the present invention is the fact that the multiplicity of vertical dead'air spaces results in an interlocked columnar structure of great strength. This condition and its relationship to the conventional cored concrete block is illustrated in Figure 11. Attention is particularly directed to the fact vthat each of the columns formed by the sepaby terminating the cored openings a distance above. the bottom of the -block, and by closing the open tops of the openings in the manner described. This produces imperforate top and bottom surfaces for the block, which is the optimum condition from the standpoint of mortar application. l

It is obvious, however, that the advantagesl `of this invention lcan be achieved lwith a construction in which the air spaces are left open at one or both ends/for the holes are sufficiently small that during mortar application, their presence is not objectionable for the reason that they are closed during the application of mortar so that the spaces are actually dea d air spaces.

While internal vibration as described is generally suicient, if desired, form `vibration may also be employed, which may be accomplished in the manner illustrated'in Figure 7. In this instance, the pallet 6 rests on a vibrating support 36 connected by means of a rod 31 with a shaft 38 having "an eccentric weight 39 mounted thereon to produce the desired vibration.

From the foregoing description Itaken in connection with the accompanying drawings, it will be readily apparent that this invention provides an entirely new and improved building block having many advantages over building units heretofore `in use.

What I-claim as my invention is:

1. The hereindescribed method of making a building unit which consistsY in: depositing a mass of plastic material such as concrete in a mold cavity; inserting a multiplicity of slender vibrating cores into the plastic 'mass without bringing the cores into engagement with the supporting surfaces of the mold cavity;- vibrating said cores until the mass has suflicient rigidit to be self-supporting; withdrawing the 'vibra g cores;l and closing the open tops of the holes formed by the withdrawal oithe cores.

2. 'I'he hereindescrlbed method of making a building unit which consists in: depositing a mass of plastic mixture such as concrete in a form; vibrating the mass internally until it has sufficient rigidity to be self-supporting by means of vibrating cores which extend into the interior of the mass from the top thereof but are spacedfrom the bottom of the mold; withdrawing the vibrating cores to leave aplurality of open topped holes in the unit, which holes are closed at theirv bottom; and closing the open tops of the holes to form wholly concealed dead air spaces in the unit and to render the top as well as the bottom surfaces of the unit imperforate. Y

3. The hereindescribed method of making a building unit which comprises: lling. a form with a quantity of plastic mixture such as concrete in excess of the amount required to make the building unit; inserting a multiplicity of relatively slender vibrating cores having their axesparallel into the plastic mixture with a translating motion parallel .to the axes o! the, cores and so that no part of the cores contacts the form; vibrating the-cores until the mixture has sufficient rigidity to be self-supporting; -with- 'moine una.

drawing the cores from the mixture with a translating motion parallel with the axes of the cores; wiping the excess plastic material from the top of the form which closes the .open tops of the substantially small holes left by the withdrawal of the vibrating cores; and effecting relative motion between the bottom of the form and its sides to enable removal of the nished unit.

4. The hereindescribed method of makingV a building unit which consists in: placing a slab of natural stone in a mold; depositing a mass of cementitious material such as concrete in the mold alongside one face of the slab; and 'vibrating the mass internally while the mold is stationary to cause its moisture content to 'exude outwardly toward the surfaces contacting the mass to improve the bond between the stone,

and the mass.

5. The hereindescribed method of making a building unit which comprises: iilling a form with a cementitious mixture such as concrete; internally vibrating the mixture by means of a multiplicity of slender vibrating cores which extend into the mass without contacting the form; and vibrating the form and consequently the mixture independently of thevibrating cores So that the conjoint action of the internal and external vibration to which the mixture is subjected quickly solidifles the mixture to the point of being self-supporting.

6. An apparatus for making building blocks and the like comprising: a form to hold a mass of plastic material such as concrete; a plurality of vibrating cores having their axes parallel;

means supporting said cores for translating motion parallel with the axes of the cores into and out of the form and with no part thereof con- 7tacting the form in any position of the cores;

resilient means mounting the cores on said supv port for raising and lowering thecaia'ge; a plurality of depending vibrating cores; a vibrating head to which all oi.' said vibrating cores are secured; resilient means connecting said head with thecarriage; and means on the carriage for vibrating said head.

' 9. The hereindescribed-method of making a building unit which comprises: forming a multipllcity of recesses in one face of a vbuilding unity during molding thereof by substantially parallel vibratory cores free oi the walls of the mold inserted substantially through the bodyofthe' mass of which the unit is composed, said cores being o! a sizeto form recesses of relatively small cross sectional area yso that substantially the entire surface of said face is capable of supporting 'a bonding material such as mortar in the event the recesses are lett open atsaid iace of DQNALD A. MCKENZIE. 

